Patent application number | Description | Published |
20090015199 | Power Storage System - A power storage system capable of surely carrying out activation, operation, and stopping that are crucial and necessary in the use of the power storage system and appropriately addressing various kinds of abnormalities is provided. The power storage system regulates DC power from a DC power supply into prescribed voltage and current using a DC-DC converter unit for storage in a power storage unit. The power storage system includes a primary side current detecting unit, a primary side voltage detecting unit, a primary side switch unit, and a primary side filter unit on the DC power supply side (primary side) of the DC-DC converter, and a secondary side filter unit, a secondary side switch unit, a secondary side voltage detecting unit, and a secondary side current detecting unit on the power storage unit side (secondary side) of the DC-DC converter, and the on/off states of at least the primary side switch unit, the DC-DC converter unit, and the secondary side switch unit are controlled by a system control unit provided with an externally applied operation command and signals obtained from elements such as the primary side current detecting unit and the primary side voltage detecting unit. | 01-15-2009 |
20090130540 | Power storage apparatus - In a power storage apparatus, for storing DC electric power, which is configured by connecting in series a plurality of modules each including a plurality of cells connected with one another, by providing two first switches at the input portion and at the output portion of the power storage apparatus and a second switch, in series with the modules, at a connection position where the modules are connected, the voltage to ground in the apparatus is lowered. | 05-21-2009 |
20090240384 | VEHICLE CONTROLLER - There is provided a vehicle controller that is mounted in a box-shaped manner beneath the floor or on the roof of a vehicle so as to supply electric power to vehicle apparatuses. The vehicle controller is configured with a plurality of functional modules | 09-24-2009 |
20090256518 | VECTOR CONTROL DEVICE OF INDUCTION MOTOR, VECTOR CONTROL METHOD OF INDUCTION MOTOR, AND DRIVE CONTROL DEVICE OF INDUCTION MOTOR - The vector control device includes: secondary magnetic flux command computing means ( | 10-15-2009 |
20090256525 | Power storage apparatus - A power storage apparatus mounted with a plurality of connected power storage modules and capable of charging or discharging an electric power, and in which a housing is partitioned by a partition plate to be divided into a power storage area and a control device area; in the power storage area, an opening is formed, and the power storage modules are contained; in the control device area, an opening is formed, and a switching protective device section to switch and protect the power storage modules is contained; a main circuit wiring from the power storage modules is led out of the control device area via the switching protective device section; the opening of the power storage area is covered with a detachable cover; and the opening of the control device area is covered with a detachable cover independent of the cover of the opening of the power storage area. | 10-15-2009 |
20090267412 | ELECTRIC-VEHICLE CONTROLLER - There is obtained an electric-vehicle controller that prevents energy stored in a power storage unit from being discharged in the case where a collision, a derailment, or breakage of an overhead line occurs. The electric-vehicle controller is provided with a DC-to-DC converter one terminal pair of which is connected to the DC power source side of the inverter, a power storage unit that is connected to the other terminal pair of the DC-to-DC converter and stores electric power, a switch provided between the power storage unit and the DC-to-DC converter, and a control unit that opens the switch in the case where abnormal circumstances may occur or have occurred. | 10-29-2009 |
20090271056 | CONTROL APPARATUS FOR ELECTRIC CAR - In a control apparatus for an electric car, wherein an auxiliary power source device, a drive control device and a power storage system are connected in parallel; the power storage system is configured of a DC-DC converter in parallel with which a capacitor is connected, a power storage portion, and a power storage system control portion which performs the controls of the DC-DC converter and the power storage portion, and the power storage system control portion is configured so as to be capable of detecting the service interruption and grounding of an overhead line. | 10-29-2009 |
20090284199 | Electric Power Converter - There are provided an electric power converter in which common-mode noise is suppressed without causing enlargement of components, increase in the number of components, a cost hike, and the like. The electric power converter is provided with a capacitor ( | 11-19-2009 |
20090322148 | POWER CONVERTER AND CONTROLLER USING SUCH POWER CONVERTER FOR ELECTRIC ROLLING STOCK - Provided is a power converter having an inverter ( | 12-31-2009 |
20100045102 | BIDIRECTIONAL BUCK BOOST DC-DC CONVERTER, RAILWAY COACH DRIVE CONTROL SYSTEM, AND RAILWAY FEEDER SYSTEM - According to the present invention, a bidirectional buck boost DC-DC converter can be obtained, in which power can flow bidirectionally from a primary side to a secondary side and from the secondary side to the primary side, regardless of a magnitude relation between a secondary-side voltage and a primary-side voltage in a state where different DC voltage sources are connected to the primary side and the secondary side in the DC-DC converter. A direction and a magnitude of the power can be automatically controlled to a desired value continuously on instantaneous value basis. | 02-25-2010 |
20100066283 | VECTOR CONTROLLER FOR PERMANENT-MAGNET SYNCHRONOUS ELECTRIC MOTOR - A method of controlling a current command by comparing voltage with a set value needs to vary the set value depending on voltage fluctuation, which involves taking a complicated control. A vector controller for a permanent-magnet synchronous electric motor, according to the present invention, can realize with a simplified configuration a field-weakening operation in a one-pulse mode in a high speed range by providing a current command compensator that corrects a current command by a corrected current command calculated based on a modulation index. | 03-18-2010 |
20100076638 | POWER CONVERTER - In a power converter a controller determines that an AC motor is in an abnormal state when a voltage of each phase of the AC motor detected by a voltage detector is in an unbalanced state where the voltage exceeds a predetermined value, and turns an opening/closing unit OFF to prevent damage generated in the AC motor from becoming worse. Moreover, the controller determines abnormality of the opening/closing unit based on a current of each phase detected by a current detector, and the controller performs control to reduce the number of revolutions of the AC motor upon determining that at least one of the AC motor and the opening/closing unit is in an abnormal state. | 03-25-2010 |
20100079093 | ELECTRIC POWER CONVERTER - Specific anomalies and details of failures as well as measures thereagainst are described that might possibly occur in electric power converters that drive and control permanent-magnet synchronous motors. An electric power converter capable of stable operation has a protective function of taking proper measures against such failures that might possibly occur. | 04-01-2010 |
20100128502 | ELECTRIC POWER CONVERSION APPARATUS - A power converter includes: a converter ( | 05-27-2010 |
20100161162 | CONTROL APPARATUS FOR ELECTRIC VEHICLE - In a control apparatus for an electric vehicle there are provided a first inverter that drives a motor; a second inverter that supplies electric power to a load; a power storage unit that supplies electric power to the first and second inverters; and a load control unit that can control a load amount, in accordance with a power storage amount in the power storage unit, or a condition amount thereof. The load control unit can perform control of an air blower, an air conditioner, and a ventilator, for example, stopping part or all of them. | 06-24-2010 |
20100171448 | MOTOR CONTROLLING APPARATUS - A motor controlling apparatus having a controller for controlling a plurality of inverters correspondingly provided to each of a plurality of alternating-current motors is reduced in size, mass, and cost by effectively grouping operations performed by each calculation unit included in the controller. This controller for controlling the inverters includes: a first common calculation unit and a second common calculation unit that calculate and output control signals that are common to each of the inverters; individual calculation units that individually calculate and output a control signal related to each of the inverters; and a common logic calculation unit | 07-08-2010 |
20100179713 | CONTROLLING DEVICE FOR RAILWAY ELECTRIC CAR - Provided is a controlling device for a railway electric car, the controlling device being able to detect a slipping/sliding phenomenon during, in particular, high-speed travel and to exercise slipping/sliding control in an appropriate manner. A slip controlling unit | 07-15-2010 |
20100191399 | WHEEL DIAMETER MEASURING APPARATUS OF ELECTRIC VEHICLE - A wheel diameter measuring apparatus for measuring a wheel diameter of an electric vehicle of speed sensorless vector control to which a synchronous motor is applied is obtained. | 07-29-2010 |
20100253267 | POWER CONVERSION DEVICE - A power conversion device includes: an inverter that drives an alternating-current motor by converting a direct-current voltage into an alternating-current voltage of an arbitrary frequency; an alternating current disconnecting switching unit connected between the inverter and the alternating-current motor; a current detector that detects an output current of the inverter; and a controller that performs on/off-control of the plural switching elements in the inverter and switching control with respect to the switching unit, based on at least a current detected by the current detector. The controller has a configuration to be able to interrupt a fault current by setting the fault current to a state of generating a current zero point, when the fault current containing a direct-current component is generated between the inverter and the alternating-current motor. | 10-07-2010 |
20100259207 | CONTROL APPARATUS OF ALTERNATING-CURRENT MOTOR - A control apparatus of an alternating-current motor includes an inverter which is connected to a direct-current source and outputs three-phase alternating currents to the alternating-current motor, a current detector which detects a current of the alternating-current motor, a voltage command/PWM signal generation unit which calculates an output voltage command of the inverter based on a signal from the current detector and generates a pulse width modulation signal to control a switching element arranged in the inverter based on the output voltage command, and a motor current imbalance compensation unit which generates a motor current imbalance compensation amount based on the current detected by the current detector. The pulse width modulation signal is directly or indirectly adjusted at the voltage command/PWM signal generation unit based on the motor current imbalance compensation amount in accordance with a driving state of the inverter. | 10-14-2010 |
20100277111 | PERMANENT MAGNET SYNCHRONIZATION MOTOR VECTOR CONTROL DEVICE - Provided is a vector control device for a permanent magnet synchronous motor driven by an inverter. The vector control device includes: a current command generation unit for generating a d-axis current command id* and q-axis current command iq* from a given torque command T*; and a current control unit operating so that the motor current coincides with the current command. The current command generation unit includes: a d-axis basic current command generation unit for generating a first d-axis basic current command id | 11-04-2010 |
20100277871 | ELECTRIC POWER CONVERTING APPARATUS - A cooling device for cooling a plurality of switching elements included in each of a converter unit and an inverter unit includes a fin base that serves as a switching element attachment plane on which the switching elements are mounted and a plurality of fins arranged on a plane opposite to the switching element attachment plane. When an electric power converting circuit is a single- or multi-phase bridge circuit including a plurality of sets of legs each formed with a positive-side arm and a negative-side arm, the switching elements constituting the legs of different phases are arranged in a row on the fin base in a traveling direction of a railway electric car. | 11-04-2010 |
20100289439 | DRIVING CONTROLLER FOR AC MOTOR - An object is to provide a driving controller for an AC motor that can prevent generation of an excessive voltage between lines of a motor and between contacts of a motor cut-off contactor and a continuous arc between contacts of the motor cut-off contactor, regardless of the type of a fault occurred, even when a phase in which a current zero point is not generated and a phase in which a current zero point is generated coexist in a fault current that flows between an inverter and the motor. A control unit is configured to open a motor cut-off contactor not at a time when a state of a detected current is determined to be abnormal but at a time when the state of the current is determined to be normal, even when a basic contactor-close command MKC0 becomes off (L level). | 11-18-2010 |
20110030574 | ELECTRIC RAILWAY SYSTEM - An electric railway system includes an electric car and an electric-power supply device that supplies electric power to the electric car. The electric-power supply device includes a power source, and an overhead conductor portion connected to the power source. The electric car includes: a power collector installed on a roof of the electric car, having a contact conductor portion contactable to the overhead conductor portion, and being capable of raising and lowering the contact conductor portion based on an instruction from outside; a switching unit connected to the power collector, opening and closing a main circuit; an electric-power conversion device connected to the switching unit, performing an electric power conversion; an electric-power storage device connected to the electric-power conversion device; an electric motor driven by the electric-power conversion device, driving the electric car; and a control unit controlling at least the switching unit. | 02-10-2011 |
20110043149 | MOTOR CONTROLLING DEVICE - In a controlling device for a permanent magnet synchronous motor, an asynchronous pulse mode is switched to a synchronous pulse mode in a situation where a modulation factor has become equal to or larger than a first set value or in a situation where an inverter output frequency has become equal to or higher than a second set value. The synchronous pulse mode is switched to the asynchronous pulse mode in a situation where the modulation factor has become smaller than the first set value, and also, the inverter output frequency has become lower than the second set value. By setting the second set value so that the number of pulses included in a half cycle of an output voltage fundamental wave of the inverter is equal to or larger than a predetermined value, it is possible to inhibit current oscillations and torque ripples from occurring in the motor. | 02-24-2011 |
20110062908 | CONTROLLER OF MOTOR - In configuring a power conversion device to drive an alternating-current motor for an electric vehicle, the device is configured in a small size, light weight, and at a low cost, while avoiding size increase of a cooler. A current-command generating unit provided in a controller to control the alternating-current motor is adjusted not to increase a loss of an inverter in a state that the inverter as a main circuit within the power conversion device is outputting a maximum voltage that can be generated at an output voltage of a direct-current power source and when a torque command is reduced, and outputs a current command to cause the alternating-current motor to generate a torque based on the torque command. | 03-17-2011 |
20110121798 | DCDC CONVERTER - A DCDC converter includes a switching circuit, to an input end of which an input filer circuit is connected, a smoothing filter circuit connected to an output end of the switching circuit and including a reactor and a capacitor, and a control unit that feeds back a state amount of the smoothing filter circuit and turns the switching circuit on and off. The control unit includes a damping control unit that calculates, based on the voltage of the capacitor, a damping operation amount for adjusting a state amount of the smoothing filter circuit. | 05-26-2011 |
20110166736 | PROPULSION CONTROL APPARATUS FOR ELECTRIC VEHICLE - A propulsion control apparatus for an electric vehicle includes an inverter that converts a direct-current voltage into an alternating-current voltage, a power storage element, and a DCDC converter connected to the power storage element. The control apparatus further includes a circuit selector unit that selects any one of power supplied from an external power supply via a power collecting device and power supplied from the power storage element and outputs it to the inverter. A linkage control unit controls at least the DCDC converter and the circuit selector unit in a linked manner, in which the linkage control unit inputs control signals at least to the DCDC converter and the circuit selector unit and controls them in a linked manner, in accordance with each of a case where the electric vehicle travels by receiving power from the external power supply and a case where the electric vehicle travels by power from the power storage element. | 07-07-2011 |
20110175558 | POWER CONVERTING APPARATUS FOR MOTOR DRIVING - A second control unit includes a current-command generating unit that generates, based on a torque command T*, a current command of the motor, a voltage-amplitude-index calculating unit that calculates, based on the current command, a voltage amplitude index (a modulation ratio PMF), a current-command adjusting unit that generates, based on the modulation ratio PMF and a frequency FINV of the motor, a current command adjustment amount dV, and a voltage command/PWM signal generating unit including a pulsation-suppression-signal generating unit that generates, based on a DC voltage EFC, a pulsation suppression signal for suppressing a pulsation component of a power supply 2f component to generate a gate signal (a PWM signal) to an inverter. | 07-21-2011 |
20110175577 | POWER CONVERTER - A power conversion controller includes: a correction-value calculating unit that calculates a correction value DE | 07-21-2011 |
20120086369 | PROPULSION CONTROL APPARATUS FOR ELECTRIC MOTOR CAR - A propulsion control apparatus for an electric motor car includes: an inverter apparatus connected to a DC power supply; a motor connected to an output of the inverter apparatus; a converter apparatus connected to an input of the inverter apparatus; and a power storage apparatus connected to an output of the converter apparatus, is configured to charge/discharge a part of power running power or regenerative power of the motor to/from the power storage apparatus. The converter apparatus includes a converter control unit that generates, based on a regeneration state signal as a signal indicating a suppression state of the regenerative power or regenerative torque or regenerative current equivalent to the regenerative power, a charging current command value, generates a charging and discharging current command value of the converter apparatus based on the charging current command value, and performs control. | 04-12-2012 |
20120147638 | ELECTRIC POWER CONVERSION DEVICE - An electric power conversion device includes a power conversion circuit for receiving electric power from an overhead wire through an LC filter circuit composed of a reactor and a capacitor and converting the electric power to output and a control unit for controlling the power conversion circuit, wherein the control unit is provided with a delay unit for delaying the voltage across the capacitor so as to produce a first control signal, produces a second output voltage instruction from the first control signal and a first output voltage instruction specifying the magnitude of the output voltage of the converted power, and controls the power conversion circuit based on the second output voltage instruction. | 06-14-2012 |
20120181961 | POWER CONVERTING APPARATUS FOR ELECTRIC VEHICLE - A controller that controls ON/OFF of switching elements and opening/closing of an opening/closing unit based on currents detected by current detectors. The controller includes a fault detector that detects whether any of the switching elements has a short-circuit fault and outputs a signal indicating a detection result, an ON/OFF controller that sets one of the switching elements that constitutes a phase other than a first phase that involves the short-circuit fault to an ON operation state and outputs a signal for opening the opening/closing unit, and an opening/closing controller that opens an opening/closing unit connected to a third phase other than the first phase and the second phase in which one of the switching elements is set to the ON operation state by the ON/OFF controller. | 07-19-2012 |
20120212168 | AC MOTOR DRIVE CONTROL DEVICE - An AC motor drive control device including: an inverter, having a plurality of switching elements subjected to on-off control, for converting a DC voltage to an AC voltage with a desired frequency to drive an AC motor; a motor opening contactor connected between the inverter and the AC motor; a switching operation beforehand detection unit for detecting a switching operation of the motor opening contactor prior to the contact or detach of main contacts and outputting a switching operation beforehand detection signal; and a control unit having an inverter control unit for performing the on-off control for the plurality of switching elements and switching control for the motor opening contactor, and controlling the inverter based on the switching operation beforehand detection signal. | 08-23-2012 |
20120326726 | STATE-OF-CHARGE ESTIMATION APPARATUS - A state-of-charge estimation apparatus connected to a power storage device having cell batteries, and estimating a state of charge of the power storage device, the apparatus including a first SOC computation unit computing a current integration value based on a total current from a current detector detecting the total current flowing to the storage device from a power conversion device using a previous SOC value as an initial value, and outputting the integration value as a first state-of-charge estimated value, and a second SOC computation unit estimating, after discharge suspension in the storage device, an open-circuit voltage based on a total voltage on a connection point between the conversion device and the storage device, a previous value of the total voltage, and a gain with time passage after discharge suspension in the storage device, and outputting the open-circuit voltage as a second state-of-charge estimated value. | 12-27-2012 |
20130027047 | STATE-OF-CHARGE ESTIMATING APPARATUS - A state-of-charge estimating apparatus includes at least a first arithmetic unit configured to calculate, as a first estimation value, the present estimation value calculated based on a battery capacity, the last estimation value, and an electric current flowing in and out between a current control apparatus, which controls charge and discharge amounts of a power storage apparatus, and the power storage apparatus, and a second arithmetic unit configured to calculate, during constant current control, as the present value of a second estimation value, an estimation value calculated based on an equivalent circuit model of a battery and a voltage of the battery and, on the other hand, calculate, during constant voltage control, as the second estimation value, the present estimation value calculated taking into account a resistance change of the battery based on the equivalent circuit model of the battery and the voltage of the battery. | 01-31-2013 |
20130073252 | MAGNETIC-POLE POSITION DETECTION APPARATUS FOR SYNCHRONOUS MACHINES - An object is to provide a magnetic-pole position detection apparatus for synchronous machines that allows a desired accuracy of magnetic-pole position detection regardless of variation in DC voltage of a DC voltage source. Calculation means ( | 03-21-2013 |
20130106329 | CONTROL APPARATUS FOR ROTATING MACHINE | 05-02-2013 |
20130113398 | CONTROL APPARATUS FOR AC ROTARY MACHINE - A control apparatus for an AC rotary machine includes: a current detection section detecting current from a power converter to the AC rotary machine; and a control section generating a three-phase AC voltage instruction to the power converter, based on current detected by the current detection section and a torque instruction. The control section includes: an observer calculating a magnetic flux estimated value of the AC rotary machine, based on detected current and the voltage instruction; a current instruction calculation unit calculating current instruction values on rotational two axes, based on the torque instruction and the magnetic flux estimated value from the observer; and a voltage instruction calculation unit calculating the voltage instruction, based on the current instruction values from the current instruction calculation unit and the magnetic flux estimated value from the observer. | 05-09-2013 |
20130181682 | CHARGE/DISCHARGE DEVICE AND CHARGE/DISCHARGE CONTROLLING METHOD - A charge/discharge device that controls charge/discharge of an electric-power storage apparatus comprises a heating determination unit that determines whether to heat the electric-power storage apparatus based on a temperature of the electric-power storage apparatus at a time of starting up the electric-power storage apparatus, and a heating control unit that, when it is determined to heat the electric-power storage apparatus, obtains a frequency characteristic of a resistance value of an internal resistance of the electric-power storage apparatus corresponding to a temperature and a charge level of the electric-power storage apparatus and performs control of alternately repeating charge and discharge of the electric-power storage apparatus in a charge/discharge period specified based on the frequency characteristic. | 07-18-2013 |
20130229052 | CONTROL DEVICE FOR ELECTRIC VEHICLE - A control device for an electric vehicle includes a converter circuit that converts a voltage input from an external power supply to a direct current having a predetermined value and outputs the direct current to a power storage unit, an inverter circuit that receives an arbitrary power supply from the external power supply or the power storage unit and converts power to an alternating current having a predetermined value, a converter control unit that controls the converter circuit based on a detection result of an abnormal state of the converter circuit and generates a protection status signal based on the detection result, and a inverter control unit that executes emergency control with respect to the inverter circuit, when the protection status signal is input, which indicates that the converter circuit is in an abnormal state. | 09-05-2013 |
20140049197 | CONTROL APPARATUS FOR AC MOTOR - A control apparatus for an AC motor that drives and controls the AC motor includes a damping control unit that calculates a damping manipulated variable that suppresses a fluctuation in the capacitor voltage, wherein the damping control unit calculates a fluctuation rate of the capacitor voltage, calculates the damping manipulated variable based on the fluctuation rate and a predetermined value that is set as a value in a predetermined range around a maximum torque of the AC motor, generates a torque command or a current command of the AC motor based on the damping manipulated variable, and controls an inverter so as to change a current flowing in the inverter in a fluctuation suppressing direction with respect to a fluctuation in the capacitor voltage based on the torque command or the current command. | 02-20-2014 |
20140055080 | CHARGING APPARATUS - A charging apparatus includes a power receiving unit that includes a rectifier, receives AC power, and converts the AC power into DC power, a power storage device that has DC power stored therein, a DC/DC converter that can execute a bidirectional power-flow control including a control of charging to the power storage device and a control of discharging from the power storage device using an output of the rectifier, and a control unit that controls operations of the power receiving unit and the DC/DC converter. In the charging apparatus, an output voltage of the rectifier is set different from an output voltage of the DC/DC converter that is applied to an output terminal of the rectifier when the power storage device is discharged. | 02-27-2014 |
20140232112 | HYBRID-VEHICLE POWER GENERATOR CONTROL APPARATUS - A hybrid-vehicle power generator control apparatus. Based on a difference electric power value, which corresponds to the difference between an electric power generator power command value given by a higher-hierarchy control unit and an output voltage value of an electric power generator, an electric power generator control unit calculates an electric power generator rotation speed command value and based on the calculated electric power generator rotation speed command value, the electric power generator control unit PWM-controls an output of the electric-power conversion system that performs electric conversion between the electric power generator and a battery, so that the rotation speed of the electric power generator is made to keep track of the electric power generator rotation speed command value and the output electric power value of the electric power generator is made to keep track of the electric power generator power command value. | 08-21-2014 |
20140247003 | POWER CONVERSION DEVICE - A power conversion device formed of a converter for rectifying a single-phase AC voltage to a DC voltage and an inverter for driving an AC motor by converting the DC voltage to an AC voltage includes: a first compensation unit that uses a frequency component twice the frequency of the single-phase AC voltage with respect to the DC voltage outputted from the converter or a current outputted from the inverter as a compensation value for at least one of a torque command value, a current command value, a voltage command value, a frequency command value, and a phase angle command value; and a second compensation unit that uses the DC voltage outputted from the converter or a current outputted from the inverter after being subjected to low frequency cut-off processing and gain processing. | 09-04-2014 |
20140301041 | FORCED AIR COOLING-TYPE POWER CONVERSION DEVICE - Power conversion sub-blocks are combined to be configured as a power conversion block. The power conversion sub-blocks include power conversion modules including cooler base sections on which semiconductor elements are mounted and cooler fin sections provided on the rear surface side of semiconductor element mounting surfaces in the cooler base sections and cooler attachment members to which cooler fin sections are attached back to back, the cooler attachment members being configured to be capable of separating an opened section where the cooler fin sections are present and external air circulates and a closed section where the semiconductor elements are present and circulating cooling air to the cooler fin sections. | 10-09-2014 |
20140330462 | HYBRID-VEHICLE POWER GENERATION CONTROL APPARATUS - A hybrid-vehicle power generator control apparatus includes an integrated control unit that issues a driving command and a control command to an engine control unit and an electric-power conversion system control unit, respectively, based on requested electric power requested by a load apparatus, and a limiter that limits the control command from the integrated control unit such that when rotation frequency of an electric power generator is same as or lower than a predetermined value, the value of torque generated by the electric power generator becomes smaller than the value of torque generated by an engine. A limitation of the control command by the limiter prevents torques of the engine and the electric power generator from stepping out of the stable operating points. | 11-06-2014 |